FIG. 21 shows a robot 90 already known and comprising a self-propelled carriage 91 adapted to run on the road by rotating wheels 92, and a table 93 provided on the top of the carriage 91 for transporting an article as placed on the table 93.
The table 93 is forwardly or rearwardly and leftwardly or rightwardly tiltably supported by a tilting mechanism on the carriage 91, and is provided with tilt angle sensors (not shown). When the road surface is inclined and even when the carriage 91 has moved up onto an obstacle, the table 93 is tilted so as to be held horizontal and to thereby prevent an article placed on the table 93 from falling off or collapsing.
However, when the transport robot 90 travels, an inertial force due to acceleration or deceleration or a centrifugal force during turning will act on the article. When the table 93 is merely held horizontal, therefore, the article is likely to fall off or collapse, or a liquid will spill if it is being transported on the table.
An object of the present invention is to provide a table angle controlling method capable of effectively preventing an article placed on a table, for example, from falling off by tilting the table so that the synthetic vector of horizontal and gravitational accelerations which act on the table acts on the table perpendicular thereto.